Pasting and Rheological Properties of Starch Paste/Gels in a Sugar-Acid System

Abstract

This study was to investigate the impact of granule size, amylose content, and starch molecular characteristics on pasting and rheological properties of starch paste/gels in neutral (water) and sugar–acid systems. Normal rice starch (RS), waxy rice starch (WRS), normal tapioca starch (TS), and waxy tapioca starch (WTS) representing small-granule starches and intermediate-granule starches respectively, were used in the study. Impacts of granule size, AM content, and their synergistic effects resulted in different starch susceptibility to acid hydrolysis and interactions between starch and sucrose-water, yielding different paste viscosities in both systems. The high molecular weight (Mw¯) and linearity of amylopectin and amylose molecules increased the consistency of starch pastes. RS produced a stronger and more brittle gel than other starch gels in both neutral and sugar–acid systems. The results indicated the impact of the effect of granule size and amylose content on starch gel behaviors. Properties of waxy starch gels were mainly governed by amylopectin molecular characteristics, especially in the sugar–acid system. Adding sugar and acid had minor impacts on starch gel behaviors in the linear viscoelastic (LVE) region but were most evident in the nonlinear response regime of starch gels as shown in the Lissajous curves at large oscillatory strain.

Impact of Deformability and Rigidity of Starch Granules on Linear and Non-Linear Rheological Behavior of Waxy Rice Starch Gels and Applicability for Food End Uses

“…HY71 and RD12 granules were clearly larger, and their size was more uniform, compared to SMJ and RD6. The large granule size of RD12 compared to those of RD6 and SMJ is likely indicative of their characteristics within their respective cultivars, as our results are consistent with previously reported results [ 5 , 17 ]. There were no reports of granule size of HY71.…”

“…The value of G′ of an 8% native waxy maize starch gel studied by Wang et al [ 10 ] was ~8 Pa, and its tan δ of 0.6 indicated that the material was a soft gel. A 6% WRS gel studied by Boonkor et al [ 17 ] displayed a G′ of ~15 Pa and a tan δ of 0.5. Precha-Atsawanan et al [ 9 ] studied the stiffness of 15% gels from native and debranched WRS, and observed a G′ of 30 Pa for the native starch gel, with a tan δ of 0.3, and a very high G′ of 1000 Pa, with a tan δ of ~0.02 for the debranched starch.…”

“…The values for SMJ and HY71 were not significantly different (0.9). In the 6% native (granular) WRS studied by Boonkor et al [ 17 ], the Payne effect was absent, and the material showed type I non-linear behavior. The 15% native WRS studied by Precha-Atsawanan et al [ 9 ] only showed a very mild upswing in G″ around 1000% strain, and this material showed type III behavior.…”

“…The effects of granule rigidity and swollen granules of waxy starch on the rheological properties of waxy paste/gel, depend also on starch concentration, sample preparation, cooking temperatures, and shear forces [ 16 ]. The 6% w / v gels of waxy tapioca and waxy rice were considered to be AP polymer networks since their granules did not have much impact on their rheological property [ 17 ]. Wang et al [ 10 ] reported that an 8% w / w granular waxy maize starch gel/paste displayed a significantly higher storage modulus (G′) and a lower tan δ than their non-granular counterparts (G′ 10 Pa vs. G′ 3 Pa and tan δ 0.65 vs. tan δ 1.3, respectively).…”

Effect of Sprouted Buckwheat on Glycemic Index and Quality of Reconstituted Rice

“…The setback value denotes the anti-retrogradation ability and gelatinization of starch. The smaller the setback value, the better is the anti-retrogradation ability; however, it cannot easily to form gel [45]. The breakdown and setback values of instant rice, reconstituted rice, and instant reconstituted rice were significantly smaller than those of rice; this result indicates that the pasteurization stability of the puffed samples was better, and they could not be easily hardened and undergo retrogradation during cooling.…”